Homebrew PCBs

jj_winkel wrote:

> Here in France it is easy and cheap enough to get "masonry" grade
> H202 (35% in weight or 130 in volume)used for wood bleaching and
> stains removal, and HCl (33%), so my recipe for 1 liter is : 750mL
> water + 50mL H2O2 + 200mL HCl in that order, etching time is about 8
> to 10 minutes,

In the US I haven't found 35% H2O2 so I use the 3% one. Result is that I
do not have to add water to the mix.


>  But usually I only prepare 1/4 L (250 mL) enough for small boards
> everytime, as the solution cannot be kept and as it deteriorates
> rapidly it is best to throw it away.

Why do you say this. We discussed long that this solution is virtually
eternal...

bye
as